The CEO of electric-car maker Tesla and rocket startup SpaceX spent more than two-and-a-half hours Thursday night talking to podcast host Joe Rogan about what it's like inside his head ("a never-ending explosion"), keeping a car company in business ("very difficult") and trying to get governments to regulate artificial intelligence ("nobody listened").

The car company has struggled to scale up production of its Model 3 sedan, which has been hit by a number of delays, intensifying the pressure on Musk.

"It's very difficult to keep a car company alive," he said.

Smoking weed: 'It's like a cup of coffee in reverse'

Musk raised eyebrows on social media after accepting what Rogan said was a joint of marijuana and tobacco and taking a puff. "I mean, it's legal, right?" he asked.

Marijuana is legal in California
, where the interview took place, but Musk's phone later started buzzing. "I'm getting text messages from friends saying, 'What the hell are you doing smoking weed?'" he said.

Musk explained that he's "not a regular smoker of weed" because he "doesn't find it's very good for productivity."